1. Field of the Invention
This invention relates to a cutting tool of a cutting machine having a base element and a chisel holder, wherein the chisel holder has a plug-in shoulder which is retained in a plug-in receptacle of the base element, and wherein the plug-in receptacle is spatially connected with its surroundings via one or several openings.
2. Discussion of Related Art
A cutting tool is known from German Patent Reference DE 43 22 401 C2. The cutting tool contains a chisel holder and a base element which is fastened to a cylinder-shaped cutting body of a cutting machine. For fastening the chisel holder on the base element, the base element has a plug-in receptacle with a V-guide, into which a plug-in shoulder of the chisel holder can be pushed. The chisel holder is fixed in place using a pressure screw. Thus the exact positioning of the chisel holder has particular importance, also in case of repeated assembly/disassembly and exchange.
For absorbing the forces occurring during the operation, the base element has a stop, on which the chisel holder is supported. So that the effects of the stop are maintained and stress on the plug-in shoulder and the plug-in receptacle is prevented to the greatest extent possible, the chisel holder is arranged offset by an adjusting space in the area around the plug-in receptacle.
It is disadvantageous in connection with such cutting tools which are employed, for example, in road construction, that the pulverized rock and water penetrate the area of the plug-in shoulder and the plug-in receptacle. Pulverized rock and water can cause the plug-in shoulder, as well as the pressure screw, to become caught in the plug-in receptacle. Thus, the chisel holder can only be released from the base element with increased effort. Often the parts are damaged during forcible separation, which results in a more cost-intensive replacement. Also, the pulverized rock results in increased wear in this area, which leads to reduced service life and therefore to higher operating costs. While releasing the pressure screw, dirt which becomes caught on the pressure screw from the interior, is worked into the threaded receptacle of the base element and damages it. A repair or replacement of the base element which must occur then can only be performed with added outlay, because customarily the base element is welded to the cutting cylinder tube and the adjacent base elements.
Dirt on the plug-in shoulder of the chisel holder and in the area of the plug-in receptacle of the base element is particularly disadvantageous. The particles adhering there are shattered during subsequent operation of the machine. Play is then created between the plug-in shoulder and the plug-in receptacle. The exactly fitted positioning of the chisel holder is then no longer assured. This has a negative effect, in particular during so-called fine milling. This method, which is gaining importance in actual use, is used to mill road surfaces to their final quality in one processing step. A prerequisite for this is that the chisel holders are exactly positioned. If one chisel holder does not meet these criteria, it causes a wrong spot in the milling pattern, which has an effect on the total result. Thus, a chisel holder which is seated loosely in the base element can decisively worsen the milling quality. Also, the loosely seated chisel can become completely separated from the base element and seriously damage the tool.